Frost Dates for Costa Mesa, CA
In Costa Mesa, CA, the average last spring frost is around Jan 5 and the average first fall frost around Dec 25, for a growing season of about 365 days. For frost-tender plants, wait until Feb 2, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Tustin Irvine Rch, CA weather station, 9 miles away, elevation 235 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | Feb 2 | Dec 3 |
| 20% | Jan 23 | Dec 9 |
| 30% | Jan 14 | Dec 13 |
| 40% | Jan 9 | Dec 19 |
| 50% | Jan 5 | Dec 25 |
| 60% | Dec 31 | Dec 30 |
| 70% | Dec 28 | Jan 3 |
| 80% | Dec 22 | Jan 9 |
| 90% | Dec 14 | Jan 20 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | Feb 1 | Dec 13 |
| Frost / freeze (32°F) | Jan 5 | Dec 25 |
| Hard freeze (28°F) | — | — |
Planting calendar for Costa Mesa
Transplant Jan 12 – Jan 26
Transplant Jan 19 – Feb 2
Transplant Jan 19 – Feb 2
Transplant Jan 12 – Jan 26
Sow or transplant Jan 12 – Jan 26
Sow or transplant Jan 12 – Jan 26
Sow or transplant Jan 19 – Feb 2
Sow or transplant Dec 8 – Dec 22
Fall sowing Oct 30 – Nov 27
Fall sowing Oct 30 – Nov 20
Fall sowing Oct 16 – Oct 30
Sow or transplant Dec 8 – Dec 22
Fall sowing Oct 16 – Nov 13
Transplant Dec 22 – Jan 5
Fall sowing Oct 2 – Oct 16
Transplant Dec 15 – Dec 29
Fall sowing Oct 2 – Oct 16
Fall sowing Oct 2 – Oct 16
Fall sowing Nov 13 – Dec 4
Fall sowing Oct 16 – Oct 30
Plant Dec 8 – Dec 22
Based on the average last frost (Jan 5) and first frost (Dec 25). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.